Sequoiadendron is a genus of evergreen trees, with two species, only one of which survives to the present: Sequoiadendron giganteum, extant known as the "giant sequoia", growing in the Sierra Nevada of California † Sequoiadendron chaneyi, the predecessor of Sequoiadendron giganteum, found in the Nevada part of the Tertiary Colorado Plateau until the late Miocene Sequoiadendron fossil pollen and macrofossils have been found as early as the Cretaceous and throughout the Northern Hemisphere, including locations in western Georgia in the Caucasus region. Media related to Sequoiadendron at Wikimedia Commons Data related to Sequoiadendron at Wikispecies
Eucalyptus is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae known as eucalypts. Plants in the genus Eucalyptus have bark, smooth, fibrous or stringy, leaves with oil glands, sepals and petals that are fused to form a "cap" or operculum over the stamens; the fruit is a woody capsule referred to as a "gumnut". Australia is covered by 92,000,000 hectares of eucalypt forest, comprising three quarters of the area covered by native forest. There most are native to Australia. One species, Eucalyptus deglupta, ranges as far north as the Philippines. Of the 15 species found outside Australia, just nine are non-Australian. Species of eucalyptus are cultivated in the tropical and temperate world, including the Americas, Africa, the Mediterranean Basin, the Middle East and the Indian subcontinent. However, the range over which many eucalypts can be planted in the temperate zone is constrained by their limited cold tolerance. On warm days, eucalyptus forests are sometimes shrouded in a smog-like mist of vaporised volatile organic compounds.
Eucalypts vary in habit from shrubs to tall trees. Trees have a single main stem or trunk but many eucalypts are mallees that are multistemmed from ground level and taller than 10 metres. There is no clear distinction between a mallee and a shrub but in eucalypts, a shrub is a mature plant less than 1 metre tall and growing in an extreme environment. E. vernicosa in the Tasmanian highlands, E. yalatensis on the Nullarbor and E. surgens growing on coastal cliffs in Western Australia are examples of eucalypt shrubs. The terms "mallet" and "marlock" are only applied to Western Australian eucalypts. A mallet is a tree with a single thin trunk with a steeply branching habit but lacks both a lignotuber and epicormic buds. E. astringens is an example of a mallet. A marlock is a shrub or small tree with a single, short trunk, that lacks a lignotuber and has spreading, densely leafy branches that reach to the ground. E. platypus is an example of a marlock. Eucalyptus trees, including mallees and marlocks, are single-stemmed and include Eucalyptus regnans, the tallest known flowering plant on Earth.
The term "morrell" is somewhat obscure in origin and appears to apply to trees of the western Australian wheatbelt and goldfields which have a long, straight trunk rough-barked. It is now used for E. longicornis and E. melanoxylon. Tree sizes follow the convention of: Small: to 10 m in height Medium-sized: 10–30 m Tall: 30–60 m Very tall: over 60 m All eucalypts add a layer of bark every year and the outermost layer dies. In about half of the species, the dead bark is shed exposing a new layer of living bark; the dead bark may be shed in ribbons or in small flakes. These species are known as "smooth barks" and include E. sheathiana, E. diversicolor, E. cosmophylla and E. cladocalyx. The remaining species retain the dead bark which accumulates. In some of these species, the fibres in the bark are loosely intertwined or more adherent. In some species the rough bark is infused with gum resin. Many species are ‘half-barks’ or ‘blackbutts’ in which the dead bark is retained in the lower half of the trunks or stems — for example, E. brachycalyx, E. ochrophloia, E. occidentalis — or only in a thick, black accumulation at the base, as in E. clelandii.
In some species in this category, for example E. youngiana and E. viminalis, the rough basal bark is ribbony at the top, where it gives way to the smooth upper stems. The smooth upper bark of the half-barks and that of the smooth-barked trees and mallees can produce remarkable colour and interest, for example E. deglupta. E. Globulus bark cells are able to photosynthesize in the absence of foliage, conferring an "increased capacity to re-fix internal CO2 following partial defoliation"; this allows the tree to grow in less-than-ideal climates, in addition to providing a better chance of recovery from damage sustained to its leaves in an event such as a fire. Different recognised types of bark include: Stringybark — consists of long fibres and can be pulled off in long pieces, it is thick with a spongy texture. Ironbark — is hard and furrowed, it is impregnated with dried kino which gives a dark red or black colour. Tessellated — bark is broken up into many distinct flakes, they can flake off. Box — has short fibres.
Some show tessellation. Ribbon -- is still loosely attached in some places, they can be firmer strips, or twisted curls. Nearly all eucalyptus are evergreen, but some tropical species lose their leaves at the end of the dry season; as in other members of the myrtle family, eucalyptus leaves are covered with oil glands. The copious oils produced are an important feature of the genus. Although mature eucalyptus trees may be towering and leafed, their shade is characteristically patchy because the leaves hang downwards; the leaves on a mature eucalyptus plant are lanceolate, petiolate alternate and waxy or glossy green. In contrast, the leaves of seedlings are opposite and glaucous, but many exceptions to this pattern exist. Many species
The Ericaceae are a family of flowering plants known as the heath or heather family, found most in acid and infertile growing conditions. The family is large, with c. 4250 known species spread across 124 genera, making it the 14th most species-rich family of flowering plants. The many well-known and economically important members of the Ericaceae include the cranberry, huckleberry and various common heaths and heathers; the Ericaceae contain a morphologically diverse range of taxa, including herbs, dwarf shrubs and trees. Their leaves are alternate or whorled and without stipules, their flowers show considerable variability. The petals are fused with shapes ranging from narrowly tubular to funnelform or urn-shaped; the corollas are radially symmetrical and urn-shaped, but many flowers of the genus Rhododendron are somewhat bilaterally symmetrical. Anthers open by pores. Adanson used the term Vaccinia to describe a similar family, but Jussieu first used the term Ericaceae; the name comes from the type genus Erica.
The exact meaning is difficult to interpret, but some sources show it as meaning'heather'. The name may have been used informally to refer to the plants before Linnaean times, been formalised when Linnaeus described Erica in 1753, again when Jussieu described the Ericaceae in 1789; the Ericaceae included both subfamilies and tribes. In 1971, who outlined the history from 1876 and in some instances 1839, recognised six subfamilies, further subdivided four of the subfamilies into tribes, the Rhododendroideae having seven tribes. Within tribe Rhodoreae, five genera were described, Rhododendron L. Therorhodion Small, Ledum L. Tsusiophyllum Max. Menziesia J. E. Smith, that were transferred into Rhododendron, along with Diplarche from the monogeneric tribe Diplarcheae. In 2002, systematic research resulted in the inclusion of the recognised families Empetraceae, Monotropaceae and Pyrolaceae into the Ericaceae based on a combination of molecular, morphological and embryological data, analysed within a phylogenetic framework.
The move increased the morphological and geographical range found within the group. One possible classification of the resulting family includes 9 subfamilies, 126 genera, about 4000 species: Enkianthoideae Kron, Judd & Anderberg Pyroloideae Kosteltsky Monotropoideae Arnott Arbutoideae Niedenzu Cassiopoideae Kron & Judd Ericoideae Link Harrimanelloideae Kron & Judd Styphelioideae Sweet Vaccinioideae Arnott See the full list at List of Ericaceae genera; the Ericaceae have a nearly worldwide distribution. They are absent from continental Antarctica, parts of the high Arctic, central Greenland and central Australia, much of the lowland tropics and neotropics; the family is composed of plants that can tolerate acidic, infertile conditions. Like other stress-tolerant plants, many Ericaceae have mycorrhizal fungi to assist with extracting nutrients from infertile soils, as well as evergreen foliage to conserve absorbed nutrients; this trait is not found in the Clethraceae and Cyrillaceae, the two families most related to the Ericaceae.
Most Ericaceae form a distinctive accumulation of mycorrhizae, in which fungi grow in and around the roots and provide the plant with nutrients. The Pyroloideae are gain sugars from the mycorrhizae, as well as nutrients. In many parts of the world, a "heath" or "heathland" is an environment characterised by an open dwarf-shrub community found on low-quality acidic soils dominated by plants in the Ericaceae. A common example is Erica tetralix; this plant family is typical of peat bogs and blanket bogs. In eastern North America, members of this family grow in association with an oak canopy, in a habitat known as an oak-heath forest. In heathland, plants in the family Ericaceae serve as hostplants to Plebejus argus; some evidence suggests eutrophic rainwater can convert ericoid heaths with species such as Erica tetralix to grasslands. Nitrogen is suspect in this regard, may be causing measurable changes to the distribution and abundance of some ericaceous species. Stevens, P. F.. "A classification of the Ericaceae: subfamilies and tribes".
Botanical Journal of the Linnean Society. 64: 1–53. Doi:10.1111/j.1095-8339.1971.tb02133.x. Cafferty, Steve. "Typification of Linnaean Plant Names in Ericaceae". Taxon. 51: 751–753. Doi:10.2307/1555030. JSTOR 10.2307/1555030. Stevens, P. F.. G. H.. L.. A.. K.. S.. J.. B.. S.. M.. M.. "Ericaceae". In Kubitzki, K. Flowering Plants. Dicotyledons: Celastrales, Rosales, Ericales; the families and genera of vascular plants. 6. Springer. Pp. 145–194. ISBN 9783540065128. Ericaceae at The Plant List Ericaceae, Empetraceae, Monotr
In botany, a fruit is the seed-bearing structure in flowering plants formed from the ovary after flowering. Fruits are the means. Edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition. Accordingly, fruits account for a substantial fraction of the world's agricultural output, some have acquired extensive cultural and symbolic meanings. In common language usage, "fruit" means the fleshy seed-associated structures of a plant that are sweet or sour, edible in the raw state, such as apples, grapes, lemons and strawberries. On the other hand, in botanical usage, "fruit" includes many structures that are not called "fruits", such as bean pods, corn kernels and wheat grains; the section of a fungus that produces spores is called a fruiting body. Many common terms for seeds and fruit do not correspond to the botanical classifications. In culinary terminology, a fruit is any sweet-tasting plant part a botanical fruit.
However, in botany, a fruit is the ripened ovary or carpel that contains seeds, a nut is a type of fruit and not a seed, a seed is a ripened ovule. Examples of culinary "vegetables" and nuts that are botanically fruit include corn, eggplant, sweet pepper, tomato. In addition, some spices, such as allspice and chili pepper, are fruits. In contrast, rhubarb is referred to as a fruit, because it is used to make sweet desserts such as pies, though only the petiole of the rhubarb plant is edible, edible gymnosperm seeds are given fruit names, e.g. ginkgo nuts and pine nuts. Botanically, a cereal grain, such as corn, rice, or wheat, is a kind of fruit, termed a caryopsis. However, the fruit wall is thin and is fused to the seed coat, so all of the edible grain is a seed; the outer edible layer, is the pericarp, formed from the ovary and surrounding the seeds, although in some species other tissues contribute to or form the edible portion. The pericarp may be described in three layers from outer to inner, the epicarp and endocarp.
Fruit that bears a prominent pointed terminal projection is said to be beaked. A fruit results from maturation of one or more flowers, the gynoecium of the flower forms all or part of the fruit. Inside the ovary/ovaries are one or more ovules where the megagametophyte contains the egg cell. After double fertilization, these ovules will become seeds; the ovules are fertilized in a process that starts with pollination, which involves the movement of pollen from the stamens to the stigma of flowers. After pollination, a tube grows from the pollen through the stigma into the ovary to the ovule and two sperm are transferred from the pollen to the megagametophyte. Within the megagametophyte one of the two sperm unites with the egg, forming a zygote, the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process; the zygote will give rise to the embryo of the seed, the endosperm mother cell will give rise to endosperm, a nutritive tissue used by the embryo.
As the ovules develop into seeds, the ovary begins to ripen and the ovary wall, the pericarp, may become fleshy, or form a hard outer covering. In some multiseeded fruits, the extent to which the flesh develops is proportional to the number of fertilized ovules; the pericarp is differentiated into two or three distinct layers called the exocarp and endocarp. In some fruits simple fruits derived from an inferior ovary, other parts of the flower, fuse with the ovary and ripen with it. In other cases, the sepals, petals and/or stamens and style of the flower fall off; when such other floral parts are a significant part of the fruit, it is called an accessory fruit. Since other parts of the flower may contribute to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms. There are three general modes of fruit development: Apocarpous fruits develop from a single flower having one or more separate carpels, they are the simplest fruits. Syncarpous fruits develop from a single gynoecium having two or more carpels fused together.
Multiple fruits form from many different flowers. Plant scientists have grouped fruits into three main groups, simple fruits, aggregate fruits, composite or multiple fruits; the groupings are not evolutionarily relevant, since many diverse plant taxa may be in the same group, but reflect how the flower organs are arranged and how the fruits develop. Simple fruits can be either dry or fleshy, result from the ripening of a simple or compound ovary in a flower with only one pistil. Dry fruits may be either dehiscent, or indehiscent. Types of dry, simple fruits, examples of each, include: achene – most seen in aggregate fruits capsule – caryopsis – cypsela – an achene-like fruit derived from the individual florets in a capitulum. Fibrous drupe – follicle – is formed from a single carpel, opens by one suture
Ecology is the branch of biology which studies the interactions among organisms and their environment. Objects of study include interactions of organisms that include biotic and abiotic components of their environment. Topics of interest include the biodiversity, distribution and populations of organisms, as well as cooperation and competition within and between species. Ecosystems are dynamically interacting systems of organisms, the communities they make up, the non-living components of their environment. Ecosystem processes, such as primary production, nutrient cycling, niche construction, regulate the flux of energy and matter through an environment; these processes are sustained by organisms with specific life history traits. Biodiversity means the varieties of species and ecosystems, enhances certain ecosystem services. Ecology is not synonymous with natural history, or environmental science, it overlaps with the related sciences of evolutionary biology and ethology. An important focus for ecologists is to improve the understanding of how biodiversity affects ecological function.
Ecologists seek to explain: Life processes and adaptations The movement of materials and energy through living communities The successional development of ecosystems The abundance and distribution of organisms and biodiversity in the context of the environment. Ecology has practical applications in conservation biology, wetland management, natural resource management, city planning, community health, economics and applied science, human social interaction. For example, the Circles of Sustainability approach treats ecology as more than the environment'out there', it is not treated as separate from humans. Organisms and resources compose ecosystems which, in turn, maintain biophysical feedback mechanisms that moderate processes acting on living and non-living components of the planet. Ecosystems sustain life-supporting functions and produce natural capital like biomass production, the regulation of climate, global biogeochemical cycles, water filtration, soil formation, erosion control, flood protection, many other natural features of scientific, economic, or intrinsic value.
The word "ecology" was coined in 1866 by the German scientist Ernst Haeckel. Ecological thought is derivative of established currents in philosophy from ethics and politics. Ancient Greek philosophers such as Hippocrates and Aristotle laid the foundations of ecology in their studies on natural history. Modern ecology became a much more rigorous science in the late 19th century. Evolutionary concepts relating to adaptation and natural selection became the cornerstones of modern ecological theory; the scope of ecology contains a wide array of interacting levels of organization spanning micro-level to a planetary scale phenomena. Ecosystems, for example, contain interacting life forms. Ecosystems are dynamic, they do not always follow a linear successional path, but they are always changing and sometimes so that it can take thousands of years for ecological processes to bring about certain successional stages of a forest. An ecosystem's area can vary from tiny to vast. A single tree is of little consequence to the classification of a forest ecosystem, but critically relevant to organisms living in and on it.
Several generations of an aphid population can exist over the lifespan of a single leaf. Each of those aphids, in turn, support diverse bacterial communities; the nature of connections in ecological communities cannot be explained by knowing the details of each species in isolation, because the emergent pattern is neither revealed nor predicted until the ecosystem is studied as an integrated whole. Some ecological principles, however, do exhibit collective properties where the sum of the components explain the properties of the whole, such as birth rates of a population being equal to the sum of individual births over a designated time frame; the main subdisciplines of ecology, population ecology and ecosystem ecology, exhibit a difference not only of scale, but of two contrasting paradigms in the field. The former focus on organisms distribution and abundance, while the focus on materials and energy fluxes; the scale of ecological dynamics can operate like a closed system, such as aphids migrating on a single tree, while at the same time remain open with regard to broader scale influences, such as atmosphere or climate.
Hence, ecologists classify ecosystems hierarchically by analyzing data collected from finer scale units, such as vegetation associations and soil types, integrate this information to identify emergent patterns of uniform organization and processes that operate on local to regional and chronological scales. To structure the study of ecology into a conceptually manageable framework, the biological world is organized into a nested hierarchy, ranging in scale from genes, to cells, to tissues, to organs, to organisms, to species, to populations, to communities, to ecosystems, to biomes, up to the level of the biosphere; this framework exhibits non-linear behaviors.
Banksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are recognised by their characteristic flower spikes and fruiting "cones" and heads. Banksias range in size from prostrate woody shrubs to trees up to 30 metres tall, they are found in a wide variety of landscapes. Heavy producers of nectar, banksias are a vital part of the food chain in the Australian bush, they are an important food source for all sorts of nectarivorous animals, including birds, rats, stingless bees and a host of invertebrates. Furthermore, they are of economic importance to Australia's cut flower industries; however these plants are threatened by a number of processes including land clearing, frequent burning and disease, a number of species are rare and endangered. Banksias grow as trees or woody shrubs. Trees of the largest species, B. integrifolia and B. seminuda grow over 15 metres tall, some grow to standing 30 metres tall. Banksia species that grow as shrubs are erect, but there are several species that are prostrate, with branches that grow on or below the soil.
The leaves of Banksia vary between species. Sizes vary from the narrow, 1–1½ centimetre long needle-like leaves of B. ericifolia, to the large leaves of B. grandis, which may be up to 45 centimetres long. The leaves of most species have serrated edges. Leaves are arranged along the branches in irregular spirals, but in some species they are crowded together in whorls. Many species have differing adult leaves; the flowers are arranged in flower spikes or capitate flower heads. The character most associated with Banksia is the flower spike, an elongated inflorescence consisting of a woody axis covered in tightly-packed pairs of flowers attached at right angles. A single flower spike contains hundreds or thousands of flowers. Not all Banksia have an elongate flower spike, however: the members of the small Isostylis complex have long been recognised as Banksias in which the flower spike has been reduced to a head. Dryandra, they have capitate flower heads rather than spikes. Banksia flowers are a shade of yellow, but orange, red and violet flowers occur.
The colour of the flowers is determined by the colour of the perianth parts and the style. The style is much longer than the perianth, is trapped by the upper perianth parts; these are released over a period of days, either from top to bottom or from bottom to top. When the styles and perianth parts are different colours, the visual effect is of a colour change sweeping along the spike; this can be most spectacular in B. prionotes and related species, as the white inflorescence in bud becomes a brilliant orange. In most cases, the individual flowers are thin saccate in shape. Multiple flower spikes can form; this is most seen in Banksia marginata and B. ericifolia. As the flower spikes or heads age, the flower parts dry up and may turn shades of orange, tan or dark brown colour, before fading to grey over a period of years. In some species, old flower parts are lost. Old flower spikes are referred to as "cones", although they are not technically cones according to the botanical definition of the term: cones only occur in conifers and cycads.
Despite the large number of flowers per inflorescence, only a few of them develop fruit, in some species a flower spike will set no fruit at all. The fruit of Banksia is a woody follicle embedded in the axis of the inflorescence. In many species, the resulting structure is a massive woody structure called a cone; each follicle consists of two horizontal valves that enclose the seeds. The follicle opens to release the seed by splitting along the suture, in some species each valve splits too. In some species the follicles open as soon as the seed is mature, but in most species most follicles open only after stimulated to do so by bushfire; each follicle contains one or two small seeds, each with a wedge-shaped papery wing that causes it to spin as it falls to the ground. Specimens of Banksia were first collected by Sir Joseph Banks and Dr Daniel Solander, naturalists on the Endeavour during Lieutenant James Cook's first voyage to the Pacific Ocean. Cook landed on Australian soil for the first time on 29 April 1770, at a place that he named Botany Bay in recognition of "the great quantity of plants Mr Banks and Dr Solander found in this place".
Over the next seven weeks and Solander collected thousands of plant specimens, including the first specimens of a new genus that would be named Banksia in Banks' honour. Four species were present in this first collection: B. serrata, B. integrifolia, B. ericifolia and B. robur. In June the ship was careened at Endeavour River; the genus Banksia was described and named by Carolus Linnaeus the Younger in his April 1782 publication Supplementum Plantarum.
Pinus contorta, with the common names lodgepole pine and shore pine, known as twisted pine, contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, but is rare in lowland rain forests. Like all pines, it is an evergreen conifer. There are four subspecies of Pinus contorta, one of them is sometimes considered to have two varieties; the subspecies are sometimes treated at the rank of variety. Pinus contorta subsp. Bolanderi: Bolander's beach pine, Bolander pine. Contorta: shore pine. Pinus contorta subsp. Murrayana: tamarack pine, or Sierra lodgepole pine. Pinus contorta subsp. Latifolia: lodgepole pine. Depending on subspecies, Pinus contorta grows as tree; the shrub form is krummholz and is 1 to 3 m high. The thin and narrow-crowned tree is 40 to 50 m high and can achieve up to 2 m in diameter at chest height; the murrayana subspecies is the tallest. The crown is rounded and the top of the tree is flattened. In dense forests, the tree has a conical crown.
The formation of twin trees is common in some populations in British Columbia. The elastic branches are difficult to break; the branches are covered with short shoots. The species name is contorta because of the twisted, bent pines found at coastal areas and the tree's twisted needles. Pinus contorta is known under several English names: black pine, scrub pine, coast pine. P. contorta subsp. Latifolia will hybridise with the related jack pine; the egg-shaped growth buds are between 20 and 30 mm long. They are short pointed rotated, resinous. Spring growth starts in beginning of April and the annual growth is completed by early July; the dark and shiny needles are pointed and 4 to 8 cm long and 0.9 to 2 mm wide. The needle edge is weak to serrated; the needles rotated about the shoots' longitudinal axes. In Alberta above 2,000 m, 1 to 5 needles occur per short shoot. A population with a high proportion of three-needled short shoots occurs in the Yukon. Needles live an average of four to six years, with a maximum of 13 years.
The cones are 3–7 centimetres long. The cones have prickles on the scales. Many populations of the Rocky Mountain subspecies, P. contorta subsp. Latifolia, have serotinous cones; this means that the cones are closed and must be exposed to high temperatures, such as from forest fires, in order to open and release their seeds. The variation in their serotiny has been correlated with mountain pine beetle attacks; the cones of the coastal Pacific subspecies, P. contorta subsp. Contorta, are non-serotinous, those of the inland Pacific subspecies, P. contorta subsp. Murrayana, are non-serotinous. Pinus contorta is a fire-dependent species, requiring wildfires to maintain healthy populations of diverse ages; the bark of the lodgepole pine is thin, minimizing the tree's defense to fire. This allows the species to maintain its place in the forest habitat. One plant community in which Pinus contorta is found is the closed-cone pine forest of coastal California. Excessive wildfire prevention disrupts the fire ecology.
The stands are so densely populated that the trees self-thin, or out-compete each other, leaving dead trees standing. These become a dry ladder fuel; when the fire reaches the crowns of the trees, it can jump from tree to tree and becomes unstoppable. The natural fire regime for this species is driven by climate; the fires occur most after years of drought. Pinus contorta occurs from the upper montane to the subalpine region; these types of forests experience a lot of moisture in the form of snow in the winter due to their altitude. The density of the tree stand prohibits the establishment of an understory. With all of that being said, the likelihood of a surface fire occurring is rare. Thus, infrequent but severe fires dominate this species. An example of the climate that plays a huge role in the fire regime of Pinus contorta is quite complex. There are three different oscillations; these are Atlantic Multi-decadal Oscillation and El Nino. A combination of these oscillations being in effect or not in effect have a global effect on the water available to these forests.
So when the AMO +, ENSO – and PDO –, there is going to be a drought and a severe subalpine fire. Suillus tomentosus, a fungus, produces specialized structures called tuberculate ectomycorrhizae with the roots of lodgepole pine; these structures have been shown to be the location of concentrations of nitrogen-fixing bacteria which contribute a significant amount of nitrogen to tree growth and allow the pines to colonize nutrient-poor sites. This species is attacked by blue stain fungus, distributed